Teleology and explanation


This page contains information from the following manuscripts:

Joo, S.*, Yousif, S. R., and Knobe, J. (Under review). Teleology beyond explanation: What factors influence teleology judgments? [Preprint available here]

Joo, S.*, Yousif, S. R., and Keil, F. C. (Under revision). Understanding ‘Why’: How implicit questions shape information preferences.

Joo, S.*, Yousif, S. R., and Keil, F. C. (In prep). Understanding ‘How’: Two kinds of mechanistic explanations underlie known explanation preferences.

* Advisee


Why do people like teleological explanations?

Suppose you see a headline that reads “Why Everyone is Angry at Facebook Over Its Political Ads Policy”. Ask yourself: what is this article going to be about?

On the one hand, this article might address how it is that people have become angry, or the chain of events involved in that process. On the other hand, it might address the purpose of people’s anger, or the goals towards which it’s directed. ‘Why’ questions like these are semantically ambiguous. In our work, however, we find that ‘why’ questions are not pragmatically ambiguous. In other words, when people encounter ‘why’ questions, they already have clear expectations about what specific kind of information is being requested.

It turns out, this difference really matters! It matters not just for how you interpret headlines, but also how we understand the philosophy and science of explanations. For example, we know that adults and children generally like teleological explanations (ones that appeal to something’s purpose). But do people really prefer teleological explanations — or do they just expect teleological explanations?

We have shown that people expect that ‘why’ questions imply ‘purpose’ questions for animals and artifacts, but ‘how’ questions for non-living natural kinds. In other words, even though ‘why’ is semantically ambiguous, people have specific thoughts about what kind of question is implied. You can see some data from one of our papers below.

These findings are straightforward, but there are broad implications. We’ll just discuss one quick example here. Some have argued that children’s endorsement of teleology implies that they believe intuitively believe in intelligent design, or that adults’ endorsements of teleology suggests that humans are intrinsically unscientific. Our view hints at a different possibility: that people’s endorsement of teleology only implies something about people’s expectations — rather than speaking to some more general principle of cognition. Below, we address some specific implications more directly.

Is teleology separable from teleological explanation?

Imagine an old dictionary, now rarely used to look up words. In setting up your work-from-home office, the dictionary is incorporated into a stand to elevate your laptop. No one in your family ever moves the book back to its shelf or questions its new function. What would you say the dictionary is for?

Asking what an object is for is the same as asking about its teleology. And teleology is often linked to explanation. For example, we might say that a knife is for cutting food, and also that the knife is the way that it is so that it can cut food. But are teleology and explanation always one in the same?

We find that people differentiate between teleology and explanation. For example, people may say that the dictionary-turned-computer-stand is for propping up a laptop — but they would understand that this new function doesn’t explain why the dictionary is the way that it is. The object is explained by its original purpose: to define words.

This isn’t just about artifacts. Consider the sentence “That forest is for hiking.” On a view in which teleology and explanation are intertwined, does this sentence imply that the forest was designed for hiking? If so, who designed the forest? Part of the goal of our view is to show that endorsement of teleological statements like these need not imply endorsement of teleological explanation. Here, it could just be that people recognize that forests are commonly used for hiking!

Do people prefer teleology or mechanism?

Cognitive scientists have offered two opposite conclusions about explanation preferences. One highlights teleological preferences to argue that human cognition is inherently theistic or unscientific (e.g., Kelemen, 2004), and the other focuses on mechanistic preferences to argue that both adults and children seek causally-rich information (e.g., Grief et al., 2006). Both of these views are well-supported over decades of research — and yet they seem fundamentally opposed.

These perspectives may be reconciled by identifying two different kinds of mechanistic explanations often utilized by proponents of each view. Etiological mechanisms describe how things came to be. Take, for instance, an explanation of how a tree grew its leaves. Constitutive mechanisms, in contrast, explain how things work. Take an explanation of how a clock ticks: This explanation would describe how the inner parts of the clock fit together to make it work in real time.

Our work shows that people generally prefer constitutive mechanistic explanations to etiological mechanistic explanations. They also generally prefer constitutive mechanistic explanations to teleological explanations This matters because different research programs have often focused on one kind of explanation or the other. Our work suggests that maybe one reason for the conflicting views about explanation preferences is that people have (inadvertently!) been studying different types of explanations.

This distinction between how things currently work vs. how they came to exist has recently gained traction in the philosophy of science, but has been completely missing from cognitive science until now. And yet these subtypes can — and do! — reshape our understanding of explanation preferences.